Preliminary Characterization of a Pleomorphic Gram-Negative Rod Associated with Avian Respiratory Disease

An unidentified, pleomorphic, gram-negative rod (PGNR) bacterium has been isolated from domestic fowl with respiratory disease. The PGNR was isolated in 5% of turkey accessions and 3% of chicken accessions, primarily from the respiratory tract. Preliminary characterization of this organism included reviewing accession records, conducting cultural and biochemical tests, and analyzing cellular fatty acids. The PGNR was also compared with other bacteria capable of inhabiting the avian respiratory system. Biochemical and cellular fatty acid analysis failed to identify the organism, however all 14 isolates were similar. Respiratory disease has been and continues to be a significant problem for the poultry industry. The large number of primary and secondary agents involved in respiratory disease, including viral, bacterial, mycotic, and parasitic agents, contributes to its complexity. The avian diagnostician is responsible for compiling infor- mation from a variety of sources and disciplines and for correlating the respiratory disease with an etiology. The significance of many secondary agents is often uncertain. A pleomorphic gram-negative rod-shaped bacterium is isolated with some frequency from fowl with respiratory disease at California Veterinary Di- agnostic Laboratory System (CVDLS) laboratories. This report is a preliminary characterization of this un- identified bacterium.